Date: Tue, 15 Jun 1999 11:16:30 -0700 From: "Justin VanAbrahams" <jvanabranopsamel.net> Subject: Re: Engine Oil
Jay <maunakea51nopsamail.com> wrote in message news:929341679.983.18nopsam.remarQ.com... > I've been sort of following the synthetic oil conversation and I'm not an > engineer. It seem of what I have been reading about different oils that > most praise using synthetic oils. What I find confusing is what kind of oil > changing schedule does one keep. I have heard 15000 miles between changes! > When do most of you synthetic oil user change your oils., 7500, 3000 or > 1500? Jay It depends mostly on the car, in my opinion. Keep in mind that these days the reason to change your oil is not so much due to any sort of degrading oil performance but instead contaminants getting into the oil supply. Your filter does a good job of removing some of these contaminants, but it a) doesn't do a perfect job and b) doesn't do a perfect job forever. On my Saab Turbos, I use only synthetic oil. I use it partially because it's available in 5w and 0w oils, which are fantastic for getting quick lubrication to the turbocharger on startup, but also because they are very resistant to any sort of heat-related breakdown. This means less chance of coking in the turbo or clogging up the relatively thin oil supply lines... I change my oil about every 3,000 miles. Depending on the kind of driving I've been doing, I sometimes let it go for as long as 4,000 or 5,000 miles. Generally speaking on Skugga, my '90 SPG, I don't let her get to 3,000 before changing it since she's used mostly for, um, higher-stress driving. On my '87 SPG, the daily driver, I tend to let changes go a little longer since it spends most of its time cruising along the freeway. One thing I make sure to do, though, is replace the oil filter at least every 10,000 miles or two oil changes, whichever comes first. This helps to be sure the oil is getting filtered at the highest level possible between changes to keep contaminants out of the oil supply. On a turbocharged engine, this is especially important, as even tiny bits of debris work very hard to foul the turbo. -Justin